Impact of inappropriate lymphadenectomy on lung metastasectomy for patients with metastatic colorectal cancer

Surgical and Interventional Management of Lung Metastasis: Surgical Assessment, Resection, Ablation, Percutaneous Interventions

The lungs are the second most common site of metastases for colorectal cancer after the liver. Pulmonary metastases can be identified at the time of diagnosis of the primary tumor, or metachronously. About 20% of patients with colorectal cancer will develop pulmonary metastases. The best options for treatment include a multidisciplinary treatment approach consisting of surgical resection whenever possible, and chemotherapy. Surgical options most often include minimally invasive segmentectomy or wedge resection, while patients unable to have surgery may benefit from radio frequency ablation or radiation treatment. Prognosis is dependent on preoperative carcinoembryonic antigen level, number, and location of metastatic lesions, and resectability of primary tumor. Overall, pulmonary metastases are best treated by complete resection whenever possible.

Correlation between preoperative CT scan and lung metastases according to surgical approach in patients with colorectal cancer

INTRODUCTION

The number of lung metastases (M1) of colorectal carcinoma (CRC) in relation to the findings of computed tomography (CT) is the object of study.

METHODS

Prospective and multicenter study of the Spanish Group for Surgery of CRC lung metastases (GECMP-CCR). The role of CT in the detection of pulmonary M1 is evaluated in 522 patients who underwent a pulmonary metastasectomy for CRC. We define M1/CT as the ratio between metastatic nodules and those found on preoperative CT. Disease-specific survival (DSS), disease-free survival (DFS), and surgical approach were analyzed using the Kaplan-Meier method.

RESULTS

93 patients were performed by video-assisted surgery (VATS) and 429 by thoracotomy. In 90%, the M1/CT ratio was ≤1, with no differences between VATS and thoracotomy (94.1% vs 89.7%, p=0.874). In the remaining 10% there were more M1s than those predicted by CT (M1/CT>1), with no differences between approaches (8.6% vs 10%, p=0.874). 51 patients with M1/CT>1, showed a lower median DSS (35.4 months vs 55.8; p=0.002) and DFS (14.2 months vs 29.3; p=0.025) compared to 470 with M1/CT≤1. No differences were observed in DSS and DFS according to VATS or thoracotomy.

CONCLUSIONS

Our study shows equivalent oncological results in the resection of M1 of CRC using VATS or thoracotomy approach. The group of patients with an M1/CT ratio >1 have a worse DSS and DFS, which may mean a more advanced disease than predicted preoperatively.

The second modification of a dedicated staging system for lung metastases

The topic of pulmonary metastases has long been of high interest and ongoing controversy. There is a group of patients with pulmonary metastases who may benefit from curative resection. It remains unclear which among them will benefit from surgery in terms of survival. This work updates a previously proposed classification system for pulmonary metastases, similar in its essence to the tumor, nodes, metastasis (TNM) classification used for primary tumors and named pmTNM classification, where 'pm' stands for 'pulmonary metastasis'. The objective is to allow future studies to explore predictive and survival prognostic factors for pulmonary metastases and separate patients who will benefit from lung metastasectomy from those who will not. The secondary aim is to provide a classification system that will allow physicians, oncologists and surgeons to speak the same language in comparing their data and assessing the results of treatment of lung metastases.

Video-assisted pulmonary metastectomy is equivalent to thoracotomy regarding resection status and survival

Background

Surgical resection of pulmonary metastases leads to prolonged survival if strictly indicated. Usually, thoracotomy with manual palpation of the entire lung with lymph node dissection or sampling is performed. The aim of this study was to evaluate the role of video-assisted thoracoscopic surgery (VATS) in pulmonary metastectomy with curative intent.

Methods

In this study, all patients with suspected pulmonary metastasis (n = 483) who visited the Center for Thoracic Surgery in Regensburg, between January 2009 and December 2017 were analysed retrospectively.

Results

A total of 251 patients underwent metastectomy with curative intent. VATS was performed in 63 (25.1%) patients, 54 (85.7%) of whom had a solitary metastasis. Wedge resection was the most performed procedure in patients treated with VATS (82.5%, n = 52) and thoracotomy (72.3%, n = 136). Postoperative revisions were necessary in nine patients (4.8%), and one patient died of pulmonary embolism after thoracotomy (0.5%). Patients were discharged significantly faster after VATS than after thoracotomy (p < 0.001). Complete (R0) resection was achieved in 89% of patients. The median recurrence-free survival was 11 months (95% confidence interval 7.9–14.1). During follow-up, eight (12.7%) patients in the VATS group and 42 (22.3%) patients in the thoracotomy group experienced recurrence (p = 0.98). The median overall survival was 61 months (95% confidence interval 46.1–75.9), and there was no significant difference with regard to the surgical method used (p = 0.34).

Conclusions

VATS metastasectomy can be considered in patients with a solitary lung metastasis. An open surgical approach with palpation of the lung showed no advantage in terms of surgical outcome or survival.

Lymphadenectomy in pulmonary metastasectomy

Lymph node (LN) removal during pulmonary metastasectomy is a prerequisite to achieve complete resection or at least collect prognostic information, but is not yet generally accepted. On average, the rate of unexpected lymph node involvement (LNI) is less than 10% in sarcoma, 20% in colorectal cancer (CRC) and 30% in renal cell carcinoma (RCC) when radical LN dissection is performed. LNI is a negative prognostic factor and presence of preoperative mediastinal disease usually leads to exclusion of the patient from metastasis surgery. Nonetheless, some authors found excellent prognoses even with mediastinal LNI in colorectal and RCC metastases when radical LN dissection was performed (median survival of 37 and 36 months, respectively). Multiple metastases, central location of the lesion followed by anatomical resections are associated with a higher LNI rate. The real prognostic influence of systematic LN dissection remains unclear. Two positive effects were described after radical lymphadenectomy: a trend for improved survival in RCC patients and a reduction of mediastinal recurrences from 23% to 0% in CRC patients. Unfortunately, there is a great number of studies that do not demonstrate any positive effect of lymphadenectomy during pulmonary metastasectomy except a pseudo stage migration effect. Future studies should not only focus on survival, but also on local and LN recurrence.

Correlation between preoperative CT scan and lung metastases according to surgical approach in patients with colorectal cancer

INTRODUCTION

The number of lung metastases (M1) of colorectal carcinoma (CRC) in relation to the findings of computed tomography (CT) is the object of study.

METHODS

Prospective and multicenter study of the Spanish Group for Surgery of CRC lung metastases (GECMP-CCR). The role of CT in the detection of pulmonary M1 is evaluated in 522 patients who underwent a pulmonary metastasectomy for CRC. We define M1/CT as the ratio between metastatic nodules and those found on preoperative CT. Disease-specific survival (DSS), disease-free survival (DFS), and surgical approach were analyzed using the Kaplan-Meier method.

RESULTS

93 patients were performed by video-assisted surgery (VATS) and 429 by thoracotomy. In 90%, the M1/CT ratio was ≤1, with no differences between VATS and thoracotomy (94.1% vs 89.7%, p=0.874). In the remaining 10% there were more M1s than those predicted by CT (M1/CT>1), with no differences between approaches (8.6% vs 10%, p=0.874). 51 patients with M1/CT>1, showed a lower median DSS (35.4 months vs 55.8; p=0.002) and DFS (14.2 months vs 29.3; p=0.025) compared to 470 with M1/CT≤1. No differences were observed in DSS and DFS according to VATS or thoracotomy.

CONCLUSIONS

Our study shows equivalent oncological results in the resection of M1 of CRC using VATS or thoracotomy approach. The group of patients with an M1/CT ratio >1 have a worse DSS and DFS, which may mean a more advanced disease than predicted preoperatively.

Precision surgery in lung metastasectomy

The value of pulmonary metastasis (PM) resection in the context of controlled primary tumor sites was shown to improve survival of patients if complete resection could be achieved. The surgeon's approach can be modulated by various parameters pertaining to safety margins including local growth properties, size, spread and location of PMs. Lymph node dissection and assessment is recommended although its impact on survival remains unclear. Thoracoscopic surgery combined to thin slice chest CT scans has shown results comparable to thoracotomy in patients with few PMs. The management of PMs should therefore be discussed on an individual, interdisciplinary basis to offer the best possible oncological and surgical results as well as to maximize long term patient survival rates.

Surgical management of colorectal lung metastases

Pulmonary metastasectomy for colorectal cancer is an established means of treatment for select patients. This article will highlight the recent evidence published in the literature related to current practices for the surgical management of colorectal lung metastases and propose a diagnostic algorithm for use in clinical practice. It will also discuss controversies related to pulmonary metastasectomy, including the optimal timing of surgery, the extent of lymph node sampling/dissection, and the extent of surgical resection.

Present indications of surgical exploration of the mediastinum

Preoperative mediastinal staging is crucial in the management of patients with non-small cell lung cancer (NSCLC), especially to define prognosis and the most proper treatment. To obtain the highest certainty level before lung resection, the current American and European guidelines for preoperative mediastinal nodal staging for NSCLC recommend getting tissue confirmation of regional nodal spread in all cases except in patients with small (≤3 cm) peripheral carcinomas with no evidence of nodal involvement on computed tomography (CT) and positron emission tomography (PET). We have a wide variety of surgical methods for mediastinal staging that are well integrated in the current preoperative algorithms. Their main indication is the validation of negative results obtained by minimally invasive endoscopic techniques. However, recent studies have reported the superiority of mediastinoscopy over endosonography methods in terms of accuracy for those tumours classified as clinical (c) N0-1 by CT and PET or with intermediate risk of N2 disease (cN1 and central tumours). Apart from the exploration of the mediastinum, other surgical procedures [parasternal mediastinotomy, extended cervical mediastinoscopy (ECM) and video-assisted thoracoscopic surgery (VATS)] allow the completion of the staging process with the assessment of the primary tumour and metastasis, exploring the lung, pleural cavity, and pericardium when it is required. Transcervical lymphadenectomies represent the evolution of mediastinoscopy and they are already considered the most reliable method for mediastinal staging, mainly in the subgroup of patients in whom endosonography methods have a low sensitivity: tumours with normal mediastinum by CT and PET. In addition to their indication for staging, these procedures have also demonstrated to be feasible as preresectional lymphadenectomy in VATS lobectomy, improving the radicality of the number of lymph nodes and lymph node stations explored, mostly for left-sided tumours for which a complete mediastinal nodal dissection is not always possible by VATS approach.

Role of major resection in pulmonary metastasectomy for colorectal cancer in the Spanish prospective multicenter study (GECMP-CCR)

BACKGROUND

Patients with pulmonary metastases from colorectal cancer (CRC) may benefit from aggressive surgical therapy. The objective of this study was to determine the role of major anatomic resection for pulmonary metastasectomy to improve survival when compared with limited pulmonary resection.

PATIENTS AND METHODS

Data of 522 patients (64.2% men, mean age 64.5 years) who underwent pulmonary resections with curative intent for CRC metastases over a 2-year period were reviewed. All patients were followed for a minimum of 3 years. Disease-specific survival (DSS) and disease-free survival (DFS) were assessed with the Kaplan-Meier method. Factors associated with DSS and DFS were analyzed using a Cox proportional hazards regression model.

RESULTS

A total of 394 (75.6%) patients underwent wedge resection, 19 (3.6%) anatomic segmentectomy, 5 (0.9%) lesser resections not described, 100 (19.3%) lobectomy, and 4 (0.8%) pneumonectomy. Accordingly, 104 (19.9%) patients were treated with major anatomic resection and 418 (80.1%) with lesser resection. Operations were carried out with video-assisted thoracoscopic surgery (VATS) in 93 patients. The overall DSS and DFS were 55 and 28.3 months, respectively. Significant differences in DSS and DFS in favor of major resection versus lesser resection (DSS median not reached versus 52.2 months, P = 0.03; DFS median not reached versus 23.9 months, P < 0.001) were found. In the multivariate analysis, major resection appeared to be a protective factor in DSS [hazard ratio (HR) 0.6, 95% confidence interval (CI) 0.41-0.96, P = 0.031] and DFS (HR 0.5, 95% CI 0.36-0.75, P < 0.001). The surgical approach (VATS versus open surgical resection) had no effect on outcome.

CONCLUSION

Major anatomic resection with lymphadenectomy for pulmonary metastasectomy can be considered in selected CRC patient with sufficient functional reserve to improve the DSS and DFS. Further prospective randomized studies are needed to confirm the present results.